Americans felt no shame in these uncouth Jacksonian tactics because Florida was American territory. Providence declared it as ours.
President Monroe also fortified the feelings of ownership over Northern America in his "Monroe Doctrine."This doctrine was when he warned Europe to "Stay out of the Western Hemisphere." This statement justified America's feelings and declared us the protectors and owners of all Northern America, as well as giving us the right to involve ourselves in all affairs concerning this land.
These concepts of providence go back even before Jackson and Monroe though. Was it not the seeds of Manifest Destiny that first landed Leif Erikson on our American shores? Was it not this concept of expansionism that brought Christopher Columbus 300 years later? What of the Pilgrims and original colonists? Though unnamed, manifest destiny has existed for as long as the soil we walk on has. When one speaks of explorers and settlers, frontiers and territories, he is talking about the manifest destiny of America. The Puritans departure from Britain and later the Louis and Clarke expedition; these are all earlier forms of this philosophy.
Manifest Destiny in Practice.
The United States now had a term to define their right to expand and possess the entire continent of North America. This term was used by expansionists to justify the acquisition of California, the Oregon territory and Alaska, and in later days the annexation of various islands on the Pacific side such as Hawaii and the Philippines.
While some were driven by what they considered G-D's will, others exploited the accepted belief of manifest destiny, and paved new routes to the west for economic purposes. The fur trappers, in search of new beaver reserves, discovered fertile land and paved mountain trails into the deep west. This drew in people of other business to try their hand on homesteads in the discovered regions and expanded the undrawn American borders a bit more each day.